Postfix stable release 2.9.4,
and legacy releases 2.8.12, 2.7.11, 2.6.17 are available.
They contain fixes and workarounds that are also part of Postfix 2.10.
All supported releases:
The local(8) delivery agent's BIFF client leaked an unprivileged UDP socket.
Fix by Jaroslav Skarvada. This bug was introduced 19990127.
The SMTP server did not reject the AUTH command while a MAIL FROM transaction
was in progress. Reported by Timo Sirainen. This bug was introduced 20000314.
Postfix 2.8 and later:
The unused "pass" trigger client could close the wrong file descriptors.
This bug was introduced with Postfix 2.8.